Aluminum /6 Rear Main Seal

Thanks for the reply. I believe you misunderstood my problem. I don't have an issue with installing the rear main seal, only with installing the upper seal retainer. With the aluminum block, both rear main seal retainers are removable, an upper and a lower. The second picture shown is the upper. The first picture is the block showing where the upper seal retainer goes. Note the groove in the top picture and then look at the corresponding back of the retainer. I would think the groove is there for a purpose but there is no corresponding lip or groove on the back of the retainer. This is where I was thinking putting silicone or RTV (in the groove). Also, the ends of the retainer have recesses similar to the bottom retainer (that does hold a seal). Even though the upper retainer fits snugly against the block, it doesn't appear to use any type of seal. This is where I'm wondering if I should use some RTV to make sure I don't develop seapage at this connection.